Firstly, thanks to that cartoon election, there was no opposition. Secondly, the tiny opposition we had back then raised hell whenever they could, so I dont know why you think they didnt. Lastly, despite the fact that public funds were used by the pml[q] to pretty much buy every single billboard in lahore to pml[q]s marketing campaign, they failed. Now its time for them to shutup and stop whining.
Did opposition of previous govt really raise issue of those mercs and bimmers you mention? If yes I'd like to see a news about it. For your "lastly" current govt has all the rights to prosecute ex-govt for using govt funding for their own marketing.
As for your suggestion for them to shutup and stop whining, I don't think that is good for any "opposition" or any democracy to function properly. Opposition's job is to keep a check on the govt and make noise about their ALL wrongs.